This disclosure relates generally to methods and devices for use in treating various ocular diseases. Glaucoma is caused by a number of different eye diseases which can produce increased intraocular pressure (IOP) in the eye. The increased pressure is often caused by a backup of aqueous humour within the eye. Over time, the increased pressure can cause damage to the optic nerve, which can lead to blindness.
One way to treat glaucoma is to implant a drainage device, or shunt, in the eye. The drainage device functions to drain aqueous humour from the anterior chamber and thereby reduce the intraocular pressure. The drainage device is typically implanted using to an invasive surgical procedure. Pursuant to one such procedure, a flap is surgically formed in the sclera. The flap is folded back to form a small cavity and a shunt is inserted into the eye through the flap. Such a procedure can be quite traumatic for the patient.
The following references describe various devices and procedures for treating glaucoma: U.S. Pat. No. 6,827,700 to Lynch, U.S. Pat. No. 6,666,841 to Bergheim, U.S. Pat. No. 6,508,779 to Suson, U.S. Pat. No. 6,544,208 to Ethier, U.S. Pat. No. 5,601,094 to Reiss, U.S. Pat. No. 6,102,045 to Nordquist, United States Patent Application 2002/0156413 to Williams, 2002/0143284 to Tu, 2003/0236483 to Ren, 2002/0193725 to Odrich, 2002/0165478 to Gharib, 2002/0133168 to Smedley, 2005/0107734, 2004/0260228 to Lynch, 2004/0102729 to Haffner, 2004/0015140 to Sheilds, 2004/0254521 to Simon, 2004/0225250 to Yablonski. The aforementioned references are all incorporated herein by reference in their entireties.
Current devices and procedures for treating glaucoma have disadvantages and in some cases only moderate success rates. The procedures are very traumatic to the eye and also require highly accurate surgical skills, such as to properly place the drainage device in a proper location. In addition, the devices that drain fluid from the anterior chamber to a subconjunctival bleb beneath a scleral flap, are prone to infection, and can occlude and cease working. This can require re-operation to remove the device and place another one, or can result in further surgeries. In addition, for agents delivered via direct injection, other complications result, and numerous office visits are required to keep a therapeutic dose resident in the eye. In view of the foregoing, there is a need for improved devices and methods for the treatment of a variety of ocular diseases.